Over at the AJAX Search API blog, they've announced the LocalSearch control for Maps API sites. This is a nifty GControl extension that adds a search box to your map. When visitors to your maps mashup enter a query, the local business results from Google are plotted on the map (and optionally, in a list overlaid on the map). The best part is that you can add this Local Search Control to your map with just one line of code:
If you have questions about the AJAX Local Search API, please post in their forum. If you have any questions about Google Maps API or creating your own custom controls, please post in the Maps API forum. Enjoy making searching easier for your mashup users!